The use of cold plasma for producing chemical substances has different advantages with respect to the traditional methods. In particular, in case of the production of nitric acid according to the reaction:2N2+5O2+2H2O→4HNO3 it is not necessary using catalysts, nor working at high temperatures and above all as raw material Ammonia is not used, but only simple ambient air or air enriched with oxygen with various techniques, such as the molecular sieves or cryoseparation or others, is used.
The known cold plasma generators are mainly constituted by two electrodes fed by a high tension or frequency electric generator, so that an electrical field is generated between the same electrodes. The field, in turn, ionizes and excites the gas molecules or atoms—typically air—existing between the electrodes, thus generating a plasma gas.
However, the plasma generators known in the art and the reactors in which they are inserted have some important limits. Such limits are mainly linked to the efficiency of the system for generating plasma which, due to its intrinsic nature, takes place in a very restricted region between the electrodes.
The just illustrated aspects strongly contain the use of the cold plasma technology in the chemical synthesis processes.